But I will point out that, back in the film age -- and more so in the pre-automated-settings age -- being able to manually set them and get them right was much more important.
- You had (stock 35 mm film rolls) 12, 24, or 36 shots to a roll of film. Particularly as a amateur photographer, developing and printing that film was a significant expense.
- Unless you had a dark room -- or, more recently, "quickie" development shops and kiosks -- you typically had at least a day between the shot and visual feedback of what you'd accomplished with it. (In "yea olden days", perhaps more like a week if you didn't want to pay "rush" fees.)
And... I guess much instruction has carried forward with a lot of inertia from those earlier times.
It seems a lot like much computer and programming instruction, when I think about it. Starting off with a lot of minutia that can be very offsetting and demotivating to many attempting to learn the art (and thereby, but for them -- thinking again of photographers -- actually secondary, the craft).
The digital age has changed this significantly. In my own circle of friends, I've observed at least two people develop from "average" snapshooters (well, one had from the start a very good natural eye) into very good amateur photographers. I don't think they would have done so starting from the perspective of shutter speed, f-stops, and tweaking exposure. But as they've learned to see and frame, they've added some of this in order to further accomplish and replicate aspects of their successes.
In the digital age, they can first "accomplish shots" and then "learn to refine". One could do that pre-digital (optionally including digital metering and exposure control), but the feedback loop was a lot slower and perhaps more circumspect.